Just reading this thread made my go into a cold sweat!!!!!!!.
Testing with hover pipes hair dryers what next, lets get out the blow torch or maybe start a small fire in a bin!!.
If you ask any of the manufactures most if not all recomend using a system like the solo ones and most do not recomend spraying the black can stuff into the heads. Anyone who tests a lot with a defuser will tell you that you get a massive build up of a greasy substance in the defuser. Now if this grease was to build up in the head it would soon start malfunctioning.
As for testing with the hover pipes and hair dryers, I will just say this if you contact the below four bodies and they say test with the hover poles and a hair dryer are the way to test smoke and heat detectors send me their written reports and I will eat my Solo test gear.
a) The manufactures of detectors (rafiki, apollo, Hochiki)
b) British Standards
c) The Health and Safety Exec
d) NIC EIC or ECA (electrical governing bodies)
Ps my opinion of Rafiki is very low, we will not stock it, Sparky's seem to love it as it has been marketed as a easy way for them to bang in a fire alarm and walk away.